Eur. Phys. J. E 7, 83-93 (2002)
DOI: 10.1140/epje/i200101159
Chiral electrostatic interaction and cholesteric liquid crystals of DNA
A.A. Kornyshev1, S. Leikin2 and S.V. Malinin1, 31 Forschungszentrum Jülich, D-52425, Jülich, Germany
2 NICHD, National Institutes of Health, Bethesda, Maryland 20892, USA
3 L.D. Landau Institute for Theoretical Physics, RAS, 117940, Kosygina 2, Moscow, Russia
leikin@helix.nih.gov
s.malinin@fz-juelich.de
(Received 31 October 2001)
Abstract
Explicit expressions for electrostatic interaction between stiff
DNA duplexes of finite length are obtained. These
expressions allow for the helical symmetry of charge
distribution on DNA molecules and reveal chiral and non-chiral
interaction terms. Asymptotic expressions at small twist angles
are applied to evaluate the cholesteric pitch and the twist
elastic constant and their dependence on the length of DNA
fragments. These estimates suggest an explanation for the large
value of the cholesteric pitch and its nonmonotonic variation
with the density of the liquid crystal. An analysis of biaxial
correlations rationalizes the driving force of the transition
from the cholesteric to hexagonal phase upon dehydration.
61.30.Cz - Molecular and microscopic models and theories of liquid crystal structure.
64.70.Md - Transitions in liquid crystals.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002
